Well drilling bit



Oct. 20, 1931. w. A. ABEGG WELL 'DRILLING BIT Filed OC. 9. 1928 PatentedOct. 20, 1931 PATENT OFFICE WALTER A A'BGG, or Los ANGELES, CALIFORNIAWELL DRILLING BIT Application filed October 9, `V19'28. Serial No.311,306.

This invention has to do with a drill or boring tool and it is a generalobject of the invention to provide an improved, effective and practicaldrilling tool useful generally l in the art of drilling and particularlyin the drilling of wells with the rotary method.

My present invention has to do, generally, with the type of drill thathas one or more rotatable Vcuttinzgf members, and it is an object of theinvention to provide a bit of this type in which the Cutting members arepositively d'riven or rotated.

VAnother object of my present invention is to provide a bit of the typementioned having a positive and direct drive to the rotatable cutters.

It is another object of the invention to provide a bit in which therotatable cutters are carried on a floating element and are driven .2.0so that the floating element rotates at the same time that theindividual cutters rotate.

A further object of this invention is to furnish a simple, practical andimproved arrangement and formation of parts in -a bit 12? of the typementioned making the bit suitable for practical use in well drilling, orthe like.

The various objects and features of my invention will be best and morefully under- 3.0 stood from the following detailed description of atypical form and application of the in-V vention, throughout whichdescription I refer to the accompanying drawings, in which:

Fig. 1 is a side elevation of the bit pro- Vided by this inventionshowing it applied to the lower end of a string of drill pipe. Fig. 2 isan enlargedlongitudinal sectional view of the bit. Fig. 3 is an endelevation of the bit being a view taken as'indicated by line w 3-3 onFig. 1, and Fig. 4 is a detail section taken as indicated by line 4-4 onFig. 2.

The bit furnished by this invention includes, generally, a shank 10 ahead 11 rotatably carried by the shank, one or more cutters 12rotatably'carried by. the head, and adrive member 13 operated by theshank to drive the cutters 12.

The shank 10 of the bit is adapted to be applied to or 'connected withthe lower end W of a'string ofdrill vpipe 14 and in practice may bevaried considerably in design and construction. For purpose of example Ihave shown a simple and typical form of shanlr. In this case the shankis of sectional construction and comprises a top section A, a middlesection B, and a bottom section C. The top section A is furnished withan upwardly projecting screw-threaded pin 155 adapted to fit acorresponding socket 16 in a drill col-lar 'or other part of the stringof drill pipe 14. In practice the top section A may be of the samediameter as the part to which Vit connects.

The middle section B of the shank is of reduced dameter and projectsdownwardly from the lower end of the section A. The section B may beVformed integralwith the 'section A or it may be a separate part screwthreaded to the section A as shown in the drawings.

The section O of the shank is at the lower end of the section B and inthe construction shown is somewhat larger in diameter than thesection Bso that it operates to retain the head 11 on the section B. The shankmay be designed so that the section C is integral with the section B orit may be made detachable as shown in the drawings. In practice theseveral Sections of the shank are screw threaded togetherV Vto form arigid or solid structure for carrying and Operating the other parts ofthe tool.

The 'bit illustrated is intended to be used with the rotary method ofdrilling and therefore the shank is provided with a centralloi'igitudinal circulation opening 17 which receives circulating fiuidfrom a string of drill pipe and discharges it at the lower end portionof the shank.

The head 11 is provided as a carrier for the cntting members 12 and ismounted on the shank so that it .is free to float or rotate during thedrilling operation. The head 'is rotatably carried on the middle portionB of the shank and is held between the end portions A and C of the shankso that it cannot be displaced from the middle section B. The head has alower end or extension 20 whi'ch extends downwardly over the lower endportion C of the shank.

A suitable thrust bearing is preferably provided between the upper endof the head 11 and the downwardly-facing shoulder 21 resented by the topsection A of the shank. lg'his' thrust bearing may include a pluralityof thrust rings 22 surrounding the middle ortion B of the shank, asclearl shown in igs. 1 and 2 of the drawings. In the preferredconstruction the rings 22 adjacent the shank section A and the head 11are keyed to the shank and head so that they are held against relatverotation with reference to these parts.

My present invention provides one or more cutters to be rotatablycarried by the head 11 .and in accordance with the broader prin- .ciplesof the invention the cutter, or cutters, as the case may be, may bearranged or mounted in various manners and may be of `various forms ortypes. F or purpose of example, I have illustrated the bit as includingtwo cutters 12 of the disk type and have shown the cutters arranged inVertical planes so that the drill in a manner similar to the cutters oft e standard form of disk bit.

In the arrangement shown the two cutters 12 are carried on a singlemounting pin 25 supported by the head 11. The pin 25 is horizontallydisposed and is arranged to intersect the central longitudinal axis ofthe tool as illustrated in Fig. 4 of the drawings. In the constructionshown the downward extension 20 of the head 11 is provided with spacedlegs 26 which project downwardly from the part 20 past the lower orbottom section C of the shank to support the pin 25 below the shank, asillustrated in the drawings. The pin 25 may be mounted between thespaced legs 26 of the head in any suitable manner. In the drawings Ihave shown the in supported in openings provided in the egs, the pinbeing supplied at one end witha head 27 engaging one leg and beingthreaded at the other end to screw thread into the ,other leg. Thisconstruction is illusti'fl'ed in Fig. 4 of the drawings.

The two cutters 12 are mounted on the pin 25 so that they are offset orspaced in opposite directions from the central axis of the tool. Inaccordance with the preferred arrangement the cutters may be located adjacent the inner sides of the spaced le's 26. The form of mounting forthe cutters shown in the drawings provides eccentric bushings 28 mountedon the pin 25 to carry the cutters 12. The eccentric bushinzs aremounted in fixed position on the pin so that they project horizontallyin opposite directions causing the 'pivotal axes of the cutters 12 to beoffset in opposite directions horizontal from the axis of the pin 25. Ihave shown key projections 304i on 'the bushings fitting opcning's 306in the legzs to prevent rotation of the bushinfzs on the pins. I wish topoint out that the outcr faces or bearing parts of the bushings whichcarry the cutters may be shaped to carry the cutters in an desiredrelation with reference to the pin. `or example the bearing faces of thebushings may be such as to carry the cutters in planes other than planesperpendicular to t ie axis of the pin 25. The bushings illustrated areprovided with fianges 30 which fit between the cutters and the innersides of the lcgs so that the cutters do not Wear against the legs.lVashers 31 are provided at the inner ls'idcs of the cutters to retainthe cutters on the bushings and a spacing sleeve 32 is located on thepin 25 between the Washers to hold the washers in place. In practice oneor more cutter rings or rollers may be rotatably supported on the sleeve32 between the was iers, illustrated in Fig. 4 of the drawings.

The cutters 12 are adapted to be driven or rotated from the drive member13 on the shank, and, in ac(.'ordance with one of the important featuresof the invention, the parts are arranged so that there is a directdriving enragement between the drive member and cutters.

T he drive member' 13 may be formed on or as a part of the shank, forinstance it may be formed integral with the bottom section C of theshank. The drive member is in the nature of a drii e pinion comprising aplurality of tceth 40 arranged symmetrically about a common center whichcenter may be concentric with the longitudinal axis of the tool. In thearrangement illustrated in the drawings the drive member or pinion 13 isformed on the lower end of the bottom section C of the shank so that itoperates between the spaced legs 26 of the head at a point spaced aboutthe pin 25 which carries the cutters.

The drive connection between the drive member 13 and cutters may beobtained through various arrangements or formation of parts, it beingapparent that a direct driving engagement can be obtained between themember 13 and cutters by providing the cutters With parts to mesh orcooperate with the teeth of the drive member' and by properly relatingthe cutters to the drive member. Where I provide cutters of the disktype as shown in the drawings, it is (lesirable to serrate or notchtheir edges or peripheral portions to form teeth 43 to mesh with theteeth 40 of the drive member 13. The cutters are proportioned as todiameter and are mounted on the pin 25 so that their toothed peripheriesmesh 'with the drive pinion at substantially diametrically oppositepoints, as shown in Figs. 3 and 4 of the drawings. Through thisarrangement the cutters 12 are driven or rotated in opposite directionsfrom the pinion or drive member 13.

In the particular case illustrated the disk cutters are plano-convex andare arranged with their flat sides faced inwardly or together. By thusforming the disks their peripheral teeth are pointed or have outerCutting edges 44. It is to be understood that the teeth of the drivepinion and those formed on the cutters mesh more or less freely orloosely allowing the cutters to be offset horizontally as shown in Fig.4 without interfering with the driving engagement between the pinion andcutters. Further, the loose meshing of the teeth together with themanner in which the teeth mesh with each other at right an gles preventsthe tool from being choked or clogged with material getting between theteeth. It will be apparent that the teeth, being formed radially on themeshing parts and being engaged at right angles, operate to clean eachother, the teeth of the pinion Operating to push material outwardly frombetween the teeth 43 of the cutters while the teeth 43 of the cuttersoperate to push material upwardly from between the teeth 40 of the drivepinion. In practice the teeth of the meshing parts may be hardened orotherwise treatcd so that they are wear resisting. Further, it will beobvious that the present construction allows the Cutting edges 44 orouter portions of the dislrs to be advantageously dressed or faced withhigh-gracie hard facing material.

From the foregoing description it is believed that the operation of thedrill will be fully understood. The drill is applied to the lower end ofa string of drill pipe 14 and is lowered into the well to be driven orrotated from the drill pipe. Rotation of the drill pipe causescorresponding rotation of the shank of the drill and the drive member13, these parts being solid or rigid on the lower end of the string ofdrill pipe. The rotation of the drive member or pinion 13 producesrotation of the cutters 12 in opposite directions causing the cutters tocut or remove the formation with which they contact. The resistance ofthe cutters to rotation about their individual axes causes driving orrotation of the head 11 with the cutters about the central Vertical axisof the tool. This rotation of the head is in the same direction as thedrive member and operates to advance or feed the individually rotatingcutters into the formation. Because of the floating or differentialaction of the head 11, the string of drill pipe 14 can be rotated at amuch higher speed than is desirable for the rotation or advancement ofthe cutters about the Vertical axis. Through this action the necessarypower can be applied to the cutters by rotating the drill pipe 14 at a.higher speed and with less force than is necessary with the ordinarytype of drilling tool. In this way the drill pipe is relieved ofexcessive strain which falls upon a drill pipe when it is rotated slowlyand with great force.

As the bit operates the cutters 12 are positively rotated or drivenabout their indiwill be apparent that proper regulation or.advaneing'foi the tool will .cause .the ,individuai ,cutters and thehead 'to rotate at the proper relative speeds hsothat .the ;bit `drillsin a most effective and efficient manner. Duringthedrillingoperation thecuttings or foreign matter getting between the teeth of the drive memberor cutters are displaced by the .75 meshing action of the teeth 40 and43 as above described. In other words, the drive pinion and toothedcutters are self-cleaning so that the bit does not mud-up in the mannercommonly experienced with bits in which the parts are not positivelydriven or are not freed of the mud or cuttings present in the bore.

Having described only a typical preferred form of my invention, I do notwish to limit-;35 myself to the specific details set forth, but wish toreserve to myself any changes or variations that may appear to thoseskilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. A drill of the character described including, a rotatable drivemember, a cutter, and means mounting the cutter for rotation about anaxis at substantially right angles to .95 the axis of the drive memberand for bodily rotation about an axis of the drive member,

- the drive member and cutter having meshing teeth, the teeth of thecutter having cutting edges.

2. A well drill including, a Vertical shank, a drive member on the lowerportion of the shank, a head rotat-ably mounted on the shank, twocutters and a single pin carried by the head supporting the cutters forrotation on spaced parallel horizontal axes so that they are incooperative engagement with the drive member at substantiallydiametrically opposite points.

3. A well drill including, a Vertical shank, a drive member on the lowerportion of the shank, a head rotatably carried on the shank and havingspaced projecting parts, a pin carried between said parts, and a cuttercarried on the pin in cooperative engagement with the drive member.

4. A well drill including, a Vertical'shank, a drive member on the lowerportion of the shank, a head rotatably carried on the shank and havingspaced projecting parts, a pin carried between said parts, and twocutters rotatably mounted on the pin to cooperatively engage the drivemember at opposite sides.

5. A well drill including, a Vertical shank, .i a drive member on thelower portion of the shank, a head rotatably carried on the shank andhaving spaced projecting parts, a pin carried between said parts, twocutters rotatably mounted on the pin to cooperatively ;5,130

en ge the drive memberv at opposite sides, an a cutter (m the pinbetween said two eutters.

` In witness that I claim the foregoing I have hereunto subscribed myname this 13th day of September, 1928.

WALTER A. ABEGG.

